thread revision 278724 
1// -*- C++ -*-
2//===--------------------------- thread -----------------------------------===//
3//
4//                     The LLVM Compiler Infrastructure
5//
6// This file is dual licensed under the MIT and the University of Illinois Open
7// Source Licenses. See LICENSE.TXT for details.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_THREAD
12#define _LIBCPP_THREAD
13
14/*
15
16    thread synopsis
17
18#define __STDCPP_THREADS__ __cplusplus
19
20namespace std
21{
22
23class thread
24{
25public:
26    class id;
27    typedef pthread_t native_handle_type;
28
29    thread() noexcept;
30    template <class F, class ...Args> explicit thread(F&& f, Args&&... args);
31    ~thread();
32
33    thread(const thread&) = delete;
34    thread(thread&& t) noexcept;
35
36    thread& operator=(const thread&) = delete;
37    thread& operator=(thread&& t) noexcept;
38
39    void swap(thread& t) noexcept;
40
41    bool joinable() const noexcept;
42    void join();
43    void detach();
44    id get_id() const noexcept;
45    native_handle_type native_handle();
46
47    static unsigned hardware_concurrency() noexcept;
48};
49
50void swap(thread& x, thread& y) noexcept;
51
52class thread::id
53{
54public:
55    id() noexcept;
56};
57
58bool operator==(thread::id x, thread::id y) noexcept;
59bool operator!=(thread::id x, thread::id y) noexcept;
60bool operator< (thread::id x, thread::id y) noexcept;
61bool operator<=(thread::id x, thread::id y) noexcept;
62bool operator> (thread::id x, thread::id y) noexcept;
63bool operator>=(thread::id x, thread::id y) noexcept;
64
65template<class charT, class traits>
66basic_ostream<charT, traits>&
67operator<<(basic_ostream<charT, traits>& out, thread::id id);
68
69namespace this_thread
70{
71
72thread::id get_id() noexcept;
73
74void yield() noexcept;
75
76template <class Clock, class Duration>
77void sleep_until(const chrono::time_point<Clock, Duration>& abs_time);
78
79template <class Rep, class Period>
80void sleep_for(const chrono::duration<Rep, Period>& rel_time);
81
82}  // this_thread
83
84}  // std
85
86*/
87
88#include <__config>
89#include <iosfwd>
90#include <__functional_base>
91#include <type_traits>
92#include <cstddef>
93#include <functional>
94#include <memory>
95#include <system_error>
96#include <chrono>
97#include <__mutex_base>
98#ifndef _LIBCPP_HAS_NO_VARIADICS
99#include <tuple>
100#endif
101#include <pthread.h>
102#include <sched.h>
103
104#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
105#pragma GCC system_header
106#endif
107
108#define __STDCPP_THREADS__ __cplusplus
109
110#ifdef _LIBCPP_HAS_NO_THREADS
111#error <thread> is not supported on this single threaded system
112#else // !_LIBCPP_HAS_NO_THREADS
113
114_LIBCPP_BEGIN_NAMESPACE_STD
115
116template <class _Tp>
117class __thread_specific_ptr
118{
119    pthread_key_t __key_;
120
121    __thread_specific_ptr(const __thread_specific_ptr&);
122    __thread_specific_ptr& operator=(const __thread_specific_ptr&);
123
124    static void __at_thread_exit(void*);
125public:
126    typedef _Tp* pointer;
127
128    __thread_specific_ptr();
129    ~__thread_specific_ptr();
130
131    _LIBCPP_INLINE_VISIBILITY
132    pointer get() const {return static_cast<_Tp*>(pthread_getspecific(__key_));}
133    _LIBCPP_INLINE_VISIBILITY
134    pointer operator*() const {return *get();}
135    _LIBCPP_INLINE_VISIBILITY
136    pointer operator->() const {return get();}
137    pointer release();
138    void reset(pointer __p = nullptr);
139};
140
141template <class _Tp>
142void
143__thread_specific_ptr<_Tp>::__at_thread_exit(void* __p)
144{
145    delete static_cast<pointer>(__p);
146}
147
148template <class _Tp>
149__thread_specific_ptr<_Tp>::__thread_specific_ptr()
150{
151    int __ec = pthread_key_create(&__key_, &__thread_specific_ptr::__at_thread_exit);
152#ifndef _LIBCPP_NO_EXCEPTIONS
153    if (__ec)
154        throw system_error(error_code(__ec, system_category()),
155                           "__thread_specific_ptr construction failed");
156#endif
157}
158
159template <class _Tp>
160__thread_specific_ptr<_Tp>::~__thread_specific_ptr()
161{
162    pthread_key_delete(__key_);
163}
164
165template <class _Tp>
166typename __thread_specific_ptr<_Tp>::pointer
167__thread_specific_ptr<_Tp>::release()
168{
169    pointer __p = get();
170    pthread_setspecific(__key_, 0);
171    return __p;
172}
173
174template <class _Tp>
175void
176__thread_specific_ptr<_Tp>::reset(pointer __p)
177{
178    pointer __p_old = get();
179    pthread_setspecific(__key_, __p);
180    delete __p_old;
181}
182
183class _LIBCPP_TYPE_VIS thread;
184class _LIBCPP_TYPE_VIS __thread_id;
185
186namespace this_thread
187{
188
189_LIBCPP_INLINE_VISIBILITY __thread_id get_id() _NOEXCEPT;
190
191}  // this_thread
192
193template<> struct _LIBCPP_TYPE_VIS_ONLY hash<__thread_id>;
194
195class _LIBCPP_TYPE_VIS_ONLY __thread_id
196{
197    // FIXME: pthread_t is a pointer on Darwin but a long on Linux.
198    // NULL is the no-thread value on Darwin.  Someone needs to check
199    // on other platforms.  We assume 0 works everywhere for now.
200    pthread_t __id_;
201
202public:
203    _LIBCPP_INLINE_VISIBILITY
204    __thread_id() _NOEXCEPT : __id_(0) {}
205
206    friend _LIBCPP_INLINE_VISIBILITY
207        bool operator==(__thread_id __x, __thread_id __y) _NOEXCEPT
208        {return __x.__id_ == __y.__id_;}
209    friend _LIBCPP_INLINE_VISIBILITY
210        bool operator!=(__thread_id __x, __thread_id __y) _NOEXCEPT
211        {return !(__x == __y);}
212    friend _LIBCPP_INLINE_VISIBILITY
213        bool operator< (__thread_id __x, __thread_id __y) _NOEXCEPT
214        {return __x.__id_ < __y.__id_;}
215    friend _LIBCPP_INLINE_VISIBILITY
216        bool operator<=(__thread_id __x, __thread_id __y) _NOEXCEPT
217        {return !(__y < __x);}
218    friend _LIBCPP_INLINE_VISIBILITY
219        bool operator> (__thread_id __x, __thread_id __y) _NOEXCEPT
220        {return   __y < __x ;}
221    friend _LIBCPP_INLINE_VISIBILITY
222        bool operator>=(__thread_id __x, __thread_id __y) _NOEXCEPT
223        {return !(__x < __y);}
224
225    template<class _CharT, class _Traits>
226    friend
227    _LIBCPP_INLINE_VISIBILITY
228    basic_ostream<_CharT, _Traits>&
229    operator<<(basic_ostream<_CharT, _Traits>& __os, __thread_id __id)
230        {return __os << __id.__id_;}
231
232private:
233    _LIBCPP_INLINE_VISIBILITY
234    __thread_id(pthread_t __id) : __id_(__id) {}
235
236    friend __thread_id this_thread::get_id() _NOEXCEPT;
237    friend class _LIBCPP_TYPE_VIS thread;
238    friend struct _LIBCPP_TYPE_VIS_ONLY hash<__thread_id>;
239};
240
241template<>
242struct _LIBCPP_TYPE_VIS_ONLY hash<__thread_id>
243    : public unary_function<__thread_id, size_t>
244{
245    _LIBCPP_INLINE_VISIBILITY
246    size_t operator()(__thread_id __v) const
247    {
248        return hash<pthread_t>()(__v.__id_);
249    }
250};
251
252namespace this_thread
253{
254
255inline _LIBCPP_INLINE_VISIBILITY
256__thread_id
257get_id() _NOEXCEPT
258{
259    return pthread_self();
260}
261
262}  // this_thread
263
264class _LIBCPP_TYPE_VIS thread
265{
266    pthread_t __t_;
267
268    thread(const thread&);
269    thread& operator=(const thread&);
270public:
271    typedef __thread_id id;
272    typedef pthread_t native_handle_type;
273
274    _LIBCPP_INLINE_VISIBILITY
275    thread() _NOEXCEPT : __t_(0) {}
276#ifndef _LIBCPP_HAS_NO_VARIADICS
277    template <class _Fp, class ..._Args,
278              class = typename enable_if
279              <
280                   !is_same<typename decay<_Fp>::type, thread>::value
281              >::type
282             >
283        explicit thread(_Fp&& __f, _Args&&... __args);
284#else  // _LIBCPP_HAS_NO_VARIADICS
285    template <class _Fp> explicit thread(_Fp __f);
286#endif
287    ~thread();
288
289#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
290    _LIBCPP_INLINE_VISIBILITY
291    thread(thread&& __t) _NOEXCEPT : __t_(__t.__t_) {__t.__t_ = 0;}
292    thread& operator=(thread&& __t) _NOEXCEPT;
293#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
294
295    _LIBCPP_INLINE_VISIBILITY
296    void swap(thread& __t) _NOEXCEPT {_VSTD::swap(__t_, __t.__t_);}
297
298    _LIBCPP_INLINE_VISIBILITY
299    bool joinable() const _NOEXCEPT {return __t_ != 0;}
300    void join();
301    void detach();
302    _LIBCPP_INLINE_VISIBILITY
303    id get_id() const _NOEXCEPT {return __t_;}
304    _LIBCPP_INLINE_VISIBILITY
305    native_handle_type native_handle() _NOEXCEPT {return __t_;}
306
307    static unsigned hardware_concurrency() _NOEXCEPT;
308};
309
310class __assoc_sub_state;
311
312class _LIBCPP_HIDDEN __thread_struct_imp;
313
314class _LIBCPP_TYPE_VIS __thread_struct
315{
316    __thread_struct_imp* __p_;
317
318    __thread_struct(const __thread_struct&);
319    __thread_struct& operator=(const __thread_struct&);
320public:
321    __thread_struct();
322    ~__thread_struct();
323
324    void notify_all_at_thread_exit(condition_variable*, mutex*);
325    void __make_ready_at_thread_exit(__assoc_sub_state*);
326};
327
328_LIBCPP_FUNC_VIS __thread_specific_ptr<__thread_struct>& __thread_local_data();
329
330#ifndef _LIBCPP_HAS_NO_VARIADICS
331
332template <class _Fp, class ..._Args, size_t ..._Indices>
333inline _LIBCPP_INLINE_VISIBILITY
334void
335__thread_execute(tuple<_Fp, _Args...>& __t, __tuple_indices<_Indices...>)
336{
337    __invoke(_VSTD::move(_VSTD::get<0>(__t)), _VSTD::move(_VSTD::get<_Indices>(__t))...);
338}
339
340template <class _Fp>
341void*
342__thread_proxy(void* __vp)
343{
344    __thread_local_data().reset(new __thread_struct);
345    std::unique_ptr<_Fp> __p(static_cast<_Fp*>(__vp));
346    typedef typename __make_tuple_indices<tuple_size<_Fp>::value, 1>::type _Index;
347    __thread_execute(*__p, _Index());
348    return nullptr;
349}
350
351template <class _Fp, class ..._Args,
352          class
353         >
354thread::thread(_Fp&& __f, _Args&&... __args)
355{
356    typedef tuple<typename decay<_Fp>::type, typename decay<_Args>::type...> _Gp;
357    _VSTD::unique_ptr<_Gp> __p(new _Gp(__decay_copy(_VSTD::forward<_Fp>(__f)),
358                                __decay_copy(_VSTD::forward<_Args>(__args))...));
359    int __ec = pthread_create(&__t_, 0, &__thread_proxy<_Gp>, __p.get());
360    if (__ec == 0)
361        __p.release();
362    else
363        __throw_system_error(__ec, "thread constructor failed");
364}
365
366#else  // _LIBCPP_HAS_NO_VARIADICS
367
368template <class _Fp>
369void*
370__thread_proxy(void* __vp)
371{
372    __thread_local_data().reset(new __thread_struct);
373    std::unique_ptr<_Fp> __p(static_cast<_Fp*>(__vp));
374    (*__p)();
375    return nullptr;
376}
377
378template <class _Fp>
379thread::thread(_Fp __f)
380{
381    std::unique_ptr<_Fp> __p(new _Fp(__f));
382    int __ec = pthread_create(&__t_, 0, &__thread_proxy<_Fp>, __p.get());
383    if (__ec == 0)
384        __p.release();
385    else
386        __throw_system_error(__ec, "thread constructor failed");
387}
388
389#endif  // _LIBCPP_HAS_NO_VARIADICS
390
391#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
392
393inline _LIBCPP_INLINE_VISIBILITY
394thread&
395thread::operator=(thread&& __t) _NOEXCEPT
396{
397    if (__t_ != 0)
398        terminate();
399    __t_ = __t.__t_;
400    __t.__t_ = 0;
401    return *this;
402}
403
404#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
405
406inline _LIBCPP_INLINE_VISIBILITY
407void swap(thread& __x, thread& __y) _NOEXCEPT {__x.swap(__y);}
408
409namespace this_thread
410{
411
412_LIBCPP_FUNC_VIS void sleep_for(const chrono::nanoseconds& ns);
413
414template <class _Rep, class _Period>
415void
416sleep_for(const chrono::duration<_Rep, _Period>& __d)
417{
418    using namespace chrono;
419    if (__d > duration<_Rep, _Period>::zero())
420    {
421        _LIBCPP_CONSTEXPR duration<long double> _Max = nanoseconds::max();
422        nanoseconds __ns;
423        if (__d < _Max)
424        {
425            __ns = duration_cast<nanoseconds>(__d);
426            if (__ns < __d)
427                ++__ns;
428        }
429        else
430            __ns = nanoseconds::max();
431        sleep_for(__ns);
432    }
433}
434
435template <class _Clock, class _Duration>
436void
437sleep_until(const chrono::time_point<_Clock, _Duration>& __t)
438{
439    using namespace chrono;
440    mutex __mut;
441    condition_variable __cv;
442    unique_lock<mutex> __lk(__mut);
443    while (_Clock::now() < __t)
444        __cv.wait_until(__lk, __t);
445}
446
447template <class _Duration>
448inline _LIBCPP_INLINE_VISIBILITY
449void
450sleep_until(const chrono::time_point<chrono::steady_clock, _Duration>& __t)
451{
452    using namespace chrono;
453    sleep_for(__t - steady_clock::now());
454}
455
456inline _LIBCPP_INLINE_VISIBILITY
457void yield() _NOEXCEPT {sched_yield();}
458
459}  // this_thread
460
461_LIBCPP_END_NAMESPACE_STD
462
463#endif // !_LIBCPP_HAS_NO_THREADS
464
465#endif  // _LIBCPP_THREAD
466